Anxiety symptoms interact with approach motivations in adolescent risk-taking

Adolescence represents a pivotal neurodevelopmental period marked by escalating anxiety symptoms and heightened approach motivations. Although anxiety is typically linked to avoidance, concurrent shifts in motivational systems and neurocircuitry may alter its behavioral and neural expression, shaping developmental trajectories and treatment response. This study investigated how approach motivations (Behavioral Activation System; BAS) interact with anxiety to influence behavior and brain function in N = 121 adolescents (ages 9-13; 44% girls; 33.1% White, 22.3% Latino, 19.8% Asian, 14.9% Black, 9.9% Mixed Race). Participants completed a decision-making task and resting-state fMRI. Dimensional analyses examined joint effects of anxiety and BAS on risk-taking behaviors, task-evoked neural activity and connectivity, and intrinsic connectivity at rest. Higher anxiety was associated with risk aversion and inhibition when BAS was low, but with risk-taking and impulsivity when BAS was high (risk-taking: β = 0.25, p = .012; inhibitory control: β = 0.13, p < .001). During risk-taking, anxiety and BAS showed interactive effects on striatal (β = -0.10, p = .006) and amygdala (β = 0.10, p = .005) activity alongside distinct effects on prefrontal-subcortical connectivity (β = -0.30, p = .014; β = 0.17, p = .01). Higher BAS was associated with stronger intrinsic prefrontal-striatal connectivity (β = 0.23, p = .012), while anxiety showed no significant resting-state effects. Findings underscore the role of reward-related systems in adolescent anxiety and support developmentally informed, personalized intervention strategies.